Periklis Tomos

A case-control study of air pollution and tobacco smoking in lung cancer among women in Athens☆

BACKGROUND A case-control study exploring the role of smoking and outdoor air pollution in the causation of lung cancer, by histologic type, in nonsmoking women, was undertaken in Athens between 1987 and 1989. METHODS One hundred one women with lung cancer and 89 comparison women with fractures or other orthopedic conditions, all permanent residents of Greater Athens, were included in the study. Smoking habits were ascertained through interviews, whereas lifetime exposure to air pollution was assessed by linking blindly lifelong residential and employment addresses of all subjects with objectively estimated or presumed air pollution levels. RESULTS The age-adjusted relative risk and 95% confidence intervals for lung cancer among current smokers compared with nonsmokers was 3.40 (1.75-6.61); it was 7.43 (2.88-19.13) among those smoking for more than 30 years and 7.46 (2.40-23.17) among those smoking more than 20 cigarettes per day. The age-adjusted relative risk was 1.70 (0.75-3.89) for adenocarcinoma and 6.45 (2.73-15.25) for other histologic types of lung cancer; statistically significant dose-response trends were evident for both histologic groups. Air pollution levels were associated with increased risk for lung cancer but the relative risk was small and statistically not significant. However, when both air pollution and duration (or quantity) of tobacco smoking, as well as their interaction, were introduced in a multiple logistic regression model, the interaction term was significant at the suggestive level of 0.10. CONCLUSION Whereas there is no effect of air pollution among nonsmokers, the relative risk contrasting extreme quartiles of air pollution among smokers of 30 years duration was 2.23. The interaction was almost exclusively accounted for by the nonadenocarcinoma lung tumors.

Experimental replacement of pig trachea with novel bioprosthesis from harp seal.

Tracheal replacement has been a challenging problem for thoracic surgeons for over half of a century. We evaluated the in-vivo performance of a new tracheal bioprosthesis derived from Harp seal (Phoca groelandica) trachea that was fixed and preserved in 0.625% buffered glutaraldehyde solution for 3 months. Ten young male pigs weighing 27–32 kg (mean, 28.7 kg) underwent replacement of a tracheal segment with this new bioprosthesis. The length of replaced trachea was 1.8–2.4 cm (mean, 2.17 cm), representing 2–3 cartilage rings. All pigs survived the operation uneventfully. No immunosuppression drugs were used. The pigs eventually developed dyspnea and were euthanized on postoperative day 17–39 (mean, 30.8 days). Macroscopic and histological analysis showed an intact bioprosthesis but near-total occlusion of the native trachea by a ring of inflammatory infiltration at the site of distal anastomosis. More experiments involving a different concentration of the preservation agent, different management, and perhaps the use of bioengineering techniques are needed to improve the performance of this novel bioprosthesis.

Platelet-Rich Plasma in Surgical Oncology

We read with great interest the article titled “Breast Reconstruction With Autologous Fat Graft Mixed With Platelet-Rich Plasma” by Gentile et al. This welldesigned clinical protocol evaluated the effects related to the use of fat grafting with platelet-rich plasma (PRP) in the improvement of fat volume in breast reconstruction. Study included patients with unilateral breast hypoplasia, patients affected by breast soft tissue defects after prosthesis removal, and others affected by outcomes of breast cancer reconstruction. After a thorough search of the literature, we found no reported evidence of PRP application on tumor excision sites. Is there any established contraindication? Much research is now devoted to determining the impact of growth factors on tumor development and progression, and the reciprocal influences of tumor products on the stromal microenvironment. A more detailed understanding of the complex parameters that govern the interactions between the tumor and vascular compartments has already helped improve anti-angiogenic strategies, not only for cancer treatment but also for preventing recurrence. The secretory proteins contained in the α-granules of platelets include platelet-derived growth factor (PDGF-AA, BB, and AB isomers), transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), platelet-derived endothelial growth factor (PDEGF), and many others. It is a fact that the release of these growth factors stimulates angiogenesis. PDGF and VEGF induce tumor lymphangiogenesis, leading to enhanced rate of nodal metastasis. Patients with breast tumors positive for PDGF have a significantly lower response rate to chemotherapy as well as significantly shorter duration of survival. In addition, patients with breast cancer who had elevated plasma PDGF levels have a significantly shorter survival. EGFR (HER) and other members of the ErbB receptor family regulate several cell biology processes, including proliferation, survival, differentiation, and tumorigenesis. TGF-β ligand is a multifunctional growth factor that regulates various cell behavior, such as cell differentiation, migration, and apoptosis. For all these reasons mentioned above, we consider the use of PRP not yet indicated in patients undergoing resection for cancer, because of the presence of growth factors that could promote tumor proliferation. Even after a tumor is excised and in order to achieve optimal survival, we must implement every single evidence-based guideline while, at the same time, exclude any maneuver, the indication of which has not been established yet. Therefore, we strongly believe that the authors should have considered this important point and analyzed it in their article; otherwise, inclusion of patients affected by outcomes of breast cancer reconstruction should have been avoided. The role of PRP in surgical oncology deserves further experimental investigation and largescale prospective randomized clinical trials.

Role of platelet-rich plasma in ischemic heart disease: An update on the latest evidence.

Myocardial infarction is the most common cause of congestive heart failure. Novel strategies such as directly reprogramming cardiac fibroblasts into cardiomyocytes are an exciting area of investigation for repair of injured myocardial tissue. The ultimate goal is to rebuild functional myocardium by transplanting exogenous stem cells or by activating native stem cells to induce endogenous repair. Cell-based myocardial restoration, however, has not penetrated broad clinical practice yet. Platelet-rich plasma, an autologous fractionation of whole blood containing high concentrations of growth factors, has been shown to safely and effectively enhance healing and angiogenesis primarily by reparative cell signaling. In this review, we collected all recent advances in novel therapies as well as experimental evidence demonstrating the role of platelet-rich plasma in ischemic heart disease, focusing on aspects that might be important for future successful clinical application.

The Belsey Mark IV: an operation with an enduring role in the management of complicated hiatal hernia

BackgroundThe Belsey Mark IV operation has been used for the management of hiatal hernia for over 40 years, but with the introduction of laparoscopic techniques its role has become questionable. To determine the current role of this procedure we present a contemporary series of patients.MethodsWe reviewed fifteen consecutive patients, mean age of 63 years, who underwent a Belsey Mark IV fundoplication for gastroesophageal reflux in the presence of a hiatal hernia in our Department from January 2005 to March 2011. Indications for the thoracic approach included paraesophageal hernias, recurrent hiatal hernias and previous upper abdominal surgery.ResultsThere was no operative mortality. Immediate postoperative morbidity included 1 case of bleeding, 1 case of pneumonia and 1 case of atrial fibrillation. The mean length of stay was 5.9 days. After a mean follow-up time of 49 months, all patients reported total or partial alleviation of their symptoms. No hernia recurrence was detected during barium swallow examination.ConclusionsThe Belsey approach is a procedure that can be useful as an alternative in selected cases when there are co-morbidities complicating the transabdominal (laparoscopic) approach.

The Effect of Autologous Platelet-Rich Plasma on Bronchial Stump Tissue Granulation after Pneumonectomy: Experimental Study

Objectives. Recent advances in perioperative management, antibiotics, and surgical materials, including mechanical staplers, have decreased the operative risk of pulmonary resection. However, bronchopleural fistula can still occur in some instances, the occurrence often being lethal. This study investigated whether platelet-rich plasma (PRP) promotes granulation of the bronchial stump after pneumonectomy. Methods. Ten pigs were randomized into two groups: (A) control or non-PRP group (pneumonectomy) and (B) PRP group (pneumonectomy and PRP application). PRP was obtained by spinning down the animals own blood and collecting the buffy coat containing platelets and white blood cells. Results. Increased platelet concentration triggered the healing process. The percentage of granulation tissue formed at the stumps was significantly higher in the PRP group of animals. This observation was confirmed when statistical analysis using Mann-Whitney U test was performed (P = 0.0268). Conclusions. PRP is easily produced with minimal basic equipment and is useful in accelerating granulation of the bronchial stump, although the timing and optimum number of applications in humans require further study. Autologous PRP is a safe, feasible, and reliable new healing promoter with potential therapeutic effects.

Unique presentation of a giant mediastinal tumor as kyphosis: a case report

IntroductionAlthough posture distortion is a common problem in elderly patients, spinal deformity caused by a thymoma has not been previously reported. Thymomas are slowly growing tumors that predominantly cause respiratory symptoms.Case presentationWe report the case of an 83-year-old woman who was admitted with a giant mediastinal mass that had caused progressive spinal distortion and weight loss to our department. The clinical and laboratory investigations that followed revealed one of the largest thymomas ever reported in the medical literature, presenting as a mass lesion placed at the left hemithorax. She underwent complete surgical excision of the tumor via a median sternotomy. Two years after the operation, she showed significant improvement in her posture, no pulmonary discomfort, and a gain of 20 kg; she remains disease free based on radiographic investigations.ConclusionsIn this case, a chronic asymmetric load on the spine resulted in an abnormal vertebral curvature deformity that presented as kyphosis.

Cardiopulmonary Bypass Assisted Resection of Mediastinal Masses

Abstract  We report a recurrent solitary fibrous tumor of the mediastinum that was encircling the right pulmonary artery. The resection of the tumor with the involved right pulmonary artery segment and sequential graft reconstruction of the vessel was facilitated by the use of cardiopulmonary bypass. We review the indications, management, and outcomes of cardiopulmonary bypass for the resection of mediastinal masses.

Video-Assisted Lung Resection Using Radiofrequency Ablation in a Porcine Model

BACKGROUND The aim of this study was to assess the feasibility, efficacy, and safety of video-assisted lingula resection using radiofrequency ablation (RFA) with internally cooled electrodes in a porcine model. MATERIALS AND METHODS Six domestic pigs underwent RFA-assisted thoracoscopic lingulectomy. RFA was the only aerostatic and hemostatic method applied throughout the operation. After 30 d, the animals were sacrificed for the study of the macroscopic and microscopic effects of the technique. RESULTS No signs of pneumothorax, blood loss, or infection were observed up to 1 mo postoperatively. There was no mortality either during or after surgery. The histopathology of the lung revealed three clearly demarcated zone lesions. CONCLUSIONS Our study demonstrates that thoracoscopic lingulectomy using RFA energy is technically feasible. RFA energy is an effective and safe aerostatic and hemostatic method in the porcine model.

Acinetobacter baumannii mediastinitis after cardiopulmonary bypass: case report and literature review.

BACKGROUND Mediastinitis resulting from surgical site infection may occur in 1% of patients undergoing median sternotomy. METHODS Case report and review of the pertinent English-language literature. RESULTS We report a case of mediastinitis caused by Acinetobacter baumannii, in a patient with multiple comorbidities who underwent cardiopulmonary bypass. Successful treatment consisted of surgical debridement, reconstruction, and ampicillin-sulbactam. CONCLUSIONS Acinetobacter baumannii should be recognized as a potential causative agent of severe postoperative mediastinitis.